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a(n) = 5^n + 6^n + 7^n.
1

%I #19 Sep 08 2022 08:45:07

%S 3,18,110,684,4322,27708,179930,1181604,7835042,52384428,352707050,

%T 2388951924,16262210162,111170407548,762690752570,5248264072644,

%U 36206628367682,250320112885068,1733788251844490,12027328411711764

%N a(n) = 5^n + 6^n + 7^n.

%H Vincenzo Librandi, <a href="/A074571/b074571.txt">Table of n, a(n) for n = 0..300</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (18,-107,210).

%F From _Mohammad K. Azarian_, Dec 30 2008: (Start)

%F G.f.: 1/(1-5*x) + 1/(1-6*x) + 1/(1-7*x).

%F E.g.f.: e^(5*x) + e^(6*x) + e^(7*x). (End)

%t Table[5^n + 6^n + 7^n, {n, 0, 20}]

%t LinearRecurrence[{18,-107,210},{3,18,110},30] (* _Harvey P. Dale_, Apr 29 2014 *)

%o (Magma) [5^n + 6^n + 7^n: n in [0..20]]; // _Vincenzo Librandi_, May 20 2011

%Y Cf. A001550, A001576, A034513, A001579, A074501-A074580.

%K easy,nonn

%O 0,1

%A _Robert G. Wilson v_, Aug 23 2002